Mastering Microbiology Chapter 8

24 July 2022
4.7 (114 reviews)
43 test answers

Unlock all answers in this set

Unlock answers (39)
question
What are the products of semiconservative replication for a double-stranded DNA molecule?
answer
Two double-stranded DNA molecules, each consisting of one parental strand and one daughter strand.
question
Why is DNA replication essential for a cell?
answer
An organism must copy its DNA to pass genetic information to its offspring.
question
What is the function of the parental DNA in replication?
answer
It serves as the template for DNA replication.
question
Which of the following is a DNA strand complementary to CGA ATC AGC?
answer
GCT TAG TCG
question
Transcription produces which of the following?
answer
mRNA, tRNA, and rRNA are all produced by transcription
question
According to the animation, which of the following makes mRNA from the information stored in a DNA template?
answer
RNA polymerase
question
Ribosomes contain which of the following?
answer
rRNA
question
Which of the following is involved in bringing amino acids to the ribosomes?
answer
tRNA
question
Which of the following can be translated into protein?
answer
mRNA
question
What results from the process of translation?
answer
a polypeptide
question
How is bacterial translation different from eukaryotic translation?
answer
Bacteria can begin translation before transcription has terminated.
question
According to the animation, ribosomes move along the mRNA in which direction?
answer
5' to 3'
question
Which of the following best describes the flow of information in cells?
answer
mRNA is made by copying specific regions of DNA called genes. Ribosomes use mRNA as instructions, which provide a code specifying the order of amino acids in a protein.
question
Which of the following statements concerning sugar utilization in E. coli is true?
answer
Bacteria growing on glucose as the sole carbon source grow faster than on lactose
question
What characteristic of DNA allows two connected DNA polymerases to synthesize both the leading and lagging strands?
answer
DNA is flexible.
question
What is the function of the connector proteins?
answer
They link the leading strand DNA polymerase and the lagging strand DNA polymerase together
question
Which DNA strand is synthesized continuously?
answer
Leading strand
question
Which of the following are terms associated with Okazaki fragments?
answer
Lagging strand, DNA ligase, and discontinuous
question
Why is the DNA synthesis of the lagging strand considered discontinuous?
answer
The synthesis is moving in the opposite direction from the replication fork.
question
As shown in the animation, the start codon also codes for which amino acid?
answer
methionine
question
How many codons code for the amino acid arginine?
answer
Six
question
GAU codes for
answer
aspartic acid
question
Which of the following amino acids is coded by only one codon?
answer
Trp
question
What would happen if the DNA sequence that coded for Cys was mutated in the third position from a U to an A?
answer
A stop codon would be introduced prematurely.
question
During the initiation step of translation, the fMet charged tRNA assembles in which site of the ribosome?
answer
P site
question
How does the ribosome know if the entering charged tRNA is correct?
answer
The anticodon on the tRNA base pairs to the codon on the mRNA
question
Where would one find an uncharged tRNA molecule in a ribosome?
answer
In the P and E sites
question
What kind of bond is formed when two amino acids join together?
answer
A peptide bond
question
How is translation terminated?
answer
When a protein called a release factor enters and binds to the A site
question
What is the inducer molecule in the lac operon?
answer
Allolactose
question
With which genetic region does the repressor protein interact?
answer
The operator region
question
When the cell is not in the presence of lactose,
answer
the repressor proteins bind to the operator.
question
What is the basic function of the lac operon?
answer
To code for enzymes involved in catabolizing lactose.
question
According to the animation, to what genetic element does the RNA polymerase bind?
answer
The promoter
question
Which of the following genetic elements is transcribed into a single mRNA
answer
The structural genes
question
Which operons are always transcribed unless deactivated?
answer
Repressible operons
question
Which operons are never transcribed unless activated?
answer
Inducible operons
question
According to the animation, where on the DNA strand does a repressor bind?
answer
The operator
question
When the cell is NOT in the presence of tryptophan,
answer
RNA polymerase can transcribe mRNA.
question
When is the repressor protein transcribed?
answer
It is always transcribed
question
Why is the tryptophan operon turned off in the presence of tryptophan?
answer
Tryptophan binds to and activates the repressor proteins; the repressor proteins, in turn, bind to the operator, preventing transcription.
question
What is the overall function of the trp operon?
answer
To ensure that the cell has a supply of tryptophan at all times
question
According to the animation, how do the repressor proteins block the transcription of the structural genes?
answer
It binds to the operator when activated.